1. Department of Gastroenterology; Murakami Memorial Hospital, Asahi University; Gifu; Japan
2. Department of Gastroenterology; Osaka Medical Center for Cancer and Cardiovascular Diseases; Osaka; Japan
3. Department of Gastroenterology; Social Insurance Kyoto Hospital; Kyoto; Japan
4. Department of Pathology; Niigata University; Niigata; Japan
5. Department of Clinical Research and Informatics; International Clinical Research Center; Research Institute; Institute Medical Center of Japan; Tokyo; Japan